Latch



Aug. 141, 1931. s. J. PURNELI.

LATCH Filed Aug. 20. 1929 2 Sheets-Sheet l 9N Wg,

Aug. ll, 1931. s.` J. PURNELL 1,817,939

, LATCH Filed Aug. 20, 19129l 2 Sheets-Sheet 2 Patented Aug. 11, 1931 PATENT QFFEC LATCH Application filed .August 20, 1929, Serial No. 387,197, and in Australia March 2?, 1929.

This invention relates to an improved latch usable for gates, house doors and other swinging frames or panels, but intended particularly for use on the doors of motor-cars and 5 other vehicles. l

The principal object of the invention is to provide a latch having simple and effective means for preventing rattling noises when the door is closed.

A further object is to provide a latch wherein friction between the sliding bolt and the side of the latch casing or housing is considerably reduced, thus enabling the latch to be opened and closed with a minimum of effort.

In the accompanying drawings Figure 1 is a sectional side View of the improved latch in closed position.

Figure 2 is a section on line A-A.

Figure 3 is a view similar to Figure l, but 20 showing the latch bolt open.

i Figure 4 is a side view of the latch bolt removed.

Figure 5 is a plan view of the bolt, showing the action of the anti-friction member.

Figure 6 is a detail view of the anti-friction member.

Figure 7 is a plan view of the casing and the bolt housing.

Figure 8 illustrates, in detail, the construction of the outer end of the latch bolt.

Figures 9 and 10 are views illustrating modifications.

As illustrated in these views, the improved latch comprises a base plate 2 secured in any suitable manner to the door and having one of its ends bent outwardly at right angles to form the usual face plate 3. Secured to the base plate 2 as by bolts 4f is a rectangular housing 5 wherein the latch bolt 6 is slidably fitted.

The forward end of the bolt extends through the usual aperture in the face plate 3 and is provided with the usual inclined surface 8 to co-act with striking plate 9 on the door frame. The rear portion of the latch bolt has a shank 10 which is slidably guided in an apertured lug 11 bent outwardly from the base plate 2. rllhe usual coiled spring 12 is fitted around the shank 10 and bears against the lug 11 to exert outward pressure on the bolt. If desired, two concentrically fitted coiled springs 12, as shown in Figure 10, may be used, the twist of one spring being arranged in the reverse direction to the other. In some cases more than two springs 12 may be used.

The forward end of the latch bolt G is provided on its inner side with a short but sharply inclined surface 13. Vhen the bolt is closed this inclined surface is adapted to enu gage the edge of the usual aperture 1a in the i striking plate, in the manner shown in Fign ure 8, and thus create a wedging action sucl as will prevent rattling of the door or of the latch bolt under the vibration of the car or vehicle. The portion of the bolt between th inclined surface 13 and the outer end of the bolt may be flat and parallel to the surface of the bolt, or, alternatively, it may be slightly inclined towards the end of the bolt. 7e Provided at the outer face of the latch bolt is an anti-friction member 15 adapted to reduce friction between the bolt and the side of its housing' 5. This anti-friction member comprises a roller 16 `arranged to operate n within a recess 17 in the bolt with its surface in rolling contact with the side of said bolt and the internal surface of the housing 5.

vThe roller 16 is mounted loosely on a pin 18 carried by a yoke 19. In some cases, the si.' pin 18 may be dispensed with in which case the ends 2O of the yoke are turned inwardly to act as pintles for the roller, see Figure 9. The yoke has a rearwardly projecting shank 21 which extends slidably through a channel 22 into a slotway 28 formed in the side ofthe bolt. A light coiled spring 24 is fitted around said shank 21 and bears at one end against a fixed washer 25 on the outer end of the shank. rlhe other end of said spring presses against a washer 2G, which is slidably fitted on the shank and engages a shoulder 27 formed at the end of the slot Away 23.

tling of the door. The roller 16 is then positioned at the rear end of the recess 17 and the spring 24 is not compressed.

During retraction of the latch bolt against its spring f12, the roller 16 is rotated to roll along tlie side of the bolt and the inner sur* face of the housing 5, thus reducing lthe friction on the bolt. lVhen the bolt is fully retracted, as shown in Figure 3, the roller 16 is positioned at the forward end of the recess 17 and the spring 24 is compressed within the slotway 23.

During the release of the latch bolt, the

action of the coiled spring 12 forces the bolt forwardly and the roller 1G is again actuated to 4reduce friction during this movement. T1ie co1n1 iression of the light spring 24 during the retraction of the bolt assists in returning the roller 16 to its normal position when the latch bolt is released.

The provision of the anti-friction member 15 enables the latch to be opened and closed with a minimum of effort and also assists in reducing wear on the bolt, particularly when the latch becomes dry through want of oiling. Furthermore, said anti-friction member can be cheaply constructed and readily incorporated in the latch during the course of manufacture.

The latch bolt may be Operated by means of `the ordinary curved lever 28, which is pivoted at 29 to the lower portion of the face plate 2. This lever. 28 extends upwardly through a gap 30 in the side of the bolt and is preferably formed with an enlarged wearing portion 31 to engage the surface of the bolt. A suitable stop as 32 may be provided to, limit the forward movement of said lever.

What I do claim is I1. An improved latch comprising, in comby said base plate, a recessed bolt slidable Ain saidhousing, a roller fitted in the recess of said bolt in rolling contact with the side of the bolt and its housing,r and a yoke in which the roller is mounted, said yoke having a rearwardly extending shank acted upon by a spring.

2. kn improved latch comprising, in combination, a base plate supporting a housing, a recessed bolt slidable in said housing, a roller fitted in the recess of said bolt so as to be in rolling contact with the side of the bolt and its housing, a yoke supporting said roller, a shank extending rearwardly from saidyoke into a slotway in the bolt, and a coiled 'spring fit-ted around said shank and acting thereonto assist in returning the roller to normal position when the bolt is released.

3. An improved latch comprising a base plate, a. housing supported by said base plate,

iso 

